1. Field of the Invention:
The present invention relates to an opener for a test handler that is used to test semiconductor devices.
2. Description of the Related Art:
As is well known to those skilled in the art, test handlers assist testers in testing semiconductor devices manufactured by predetermined processes, sort the semiconductor devices into different levels according to the test results, and load the semiconductor devices into customer trays. Such test handlers have been disclosed in many publication documents, for example, in Korean Patent Registration No. 10-0553992 (entitled “Test handler”), the entire disclosure of which is hereby incorporated by reference.
Generally, the produced semiconductor devices are loaded into the customer trays and then supplied to the test handlers. The semiconductor devices supplied to the test handlers are loaded onto a carrier board that is located at a loading position. Subsequently, the semiconductor devices are tested at a testing position while being on the carrier board. Thereafter, the semiconductor devices are unloaded into the custom trays when the carrier board is located at an unloading position. The term “carrier board” refers to a loading device that can load a plurality of semiconductor devices thereon to assist a tester to test multiple semiconductor devices at a time. Such carrier boards are classified as test trays that have been used in conventional arts, and test boards that have been newly developed.
As can be understood above, the carrier board continuously circulates along a path including the loading position, the testing position, and the unloading position. Therefore, to prevent the loaded semiconductor devices from being displaced from correct positions or losing their balance due to a shock occurring when the carrier board moves or change its posture, a holding device for holding the semiconductor devices is provided on the carrier board.
In this case, it is necessary to release the semiconductor devices from the holding device to load or unload the semiconductor devices at the loading position or the unloading position. To achieve this purpose, a separate opener for releasing the held state of the semiconductor devices is required.
One example of a technique for releasably holding semiconductor devices loaded onto inserts of a carrier board was proposed in Korean Patent Laid-open Publication No. 10-2009-0102167 (entitled “Insert opening unit for teat tray and method for mounting semiconductor devices using the same”, hereinafter, referred to as “prior art 1”), the entire disclosure of which is hereby incorporated by reference.
In general, referring to the prior art 1 (particularly, in FIGS. 1 and 8 of the prior art 1), the opening unit is configured in such a way that rotatable holding members can hold semiconductor devices, and opening pins provided on an opening plate (called a main body) of the opening unit can rotate the holding members to release the held state of the semiconductor devices.
In detail, when the opening plate is advanced towards inserts of the carrier board and brought into close contact with the inserts, the opening pins push the holding members upwards to reversely rotate the holding members so that the holding members enter the state of being able to release the semiconductor devices. When the opening plate moves away from the inserts of the carrier board, the holding members are rotated in the forward direction by the restoring force of springs so that the holding members are returned to the state of being able to hold the corresponding semiconductor devices.
To make the manipulation of the holding members using the opening pins smooth, the carrier board must not be pushed beyond an allowed level when the opening plate comes into close contact with the inserts of the carrier board. For this, as shown in FIG. 12 attached to the specification of Korean Patent Application No. 10-2009-0063752 (entitled: Insert opener, insert and carrier board), the entire disclosure of which is hereby incorporated by reference, a separate guide rail was proposed to prevent the carrier board from being pushed.
Meanwhile, BGA type semiconductor devices have ball-shaped electrical contact points on the rear surface thereof. As shown in FIG. 9 of Korean Patent Laid-open Publication No. 10-2009-0084007 (entitled: “Carrier board type insert for test handler”), the entire disclosure of which is hereby incorporated by reference, a plurality of opening holes are formed in the bottom of a loading portion of the insert so that balls of a BGA type semiconductor device are inserted into the corresponding openings. As such, in the case of the insert having the opening holes (or depressions), if the opening holes are distorted by defects of the insert, for example, being twisted, the balls of the semiconductor device that have been inserted into the opening holes may be undesirably tightly caught by the opening holes. This causes a defect of the operation of unloading the semiconductor devices from the inserts. In other words, when unloading, a pick-and-place apparatus for transporting the semiconductor devices may not be able to correctly hold the semiconductor devices to transport them from the insert.
The defects of the insert result from the fact that the upper surface of the opening plate is not parallel to the inserts of the carrier board due to defective production or the carrier board being bent with the passage of time so that when the opening plate comes into contact with the inserts, the contact pressure of the opening plate cannot be evenly applied to the inserts. In other words, the contact pressure of the opening plate that is continuously unevenly applied to the rear surfaces of the inserts becomes a factor resulting in a defect of the insert, for example, causing a twist of the insert. Furthermore, if the opening plate is not horizontally advanced to the inserts of the carrier board, the opening plate cannot uniformly apply force to the inserts (in the case of the opening plate described below, 32 holding members of the inserts are simultaneously operated by only one opening plate); for example, excessive force may be unevenly applied to some of the inserts, thus causing a twist of the inserts.
The above problems of the inserts being twisted are more frequently caused in an insert disposed in FIG. 5b of Korean Patent Application No. 10-2009-0063752, the entire disclosure of which is hereby incorporated by reference. This insert shown in FIG. 5b of No. 10-2009-0063752 is configured such that seating surfaces onto which semiconductor devices are placed are separated from each other, unlike Korean Patent Application No. 10-2009-0063752 in which the seating surfaces are integrated together, so that the insert is easily twisted by slight uneven force applied to the lower surface of the insert. Therefore, the inserts have been typically produced in such a way that the seating surfaces of the insert are integrated together to more reliably resist a twist compared to the case of FIG. 5b of No. 10-2009-0063752. However, if a customer requires a structure in which the seating surfaces of the insert are separated from each other to use the portions by which the seating surfaces are separated for other purposes, the insert may avoidably have the structure of FIG. 5b of No. 10-2009-0063752.